Powering autonomous sensors with miniaturized piezoelectric based energy harvesting devices operating at very low frequency

• Published in: Journal of physics. Conference series Vol. 660; no. 1; pp. 12085 - 12089
• Main Authors: Ferin, G, Bantignies, C, Khanh, H Le, Flesch, E, Nguyen-Dinh, A
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 10.12.2015
• Subjects: Biocompatibility; Electronic implants; Energy harvesting; Frequency spectrum; Internet of Things; Medical electronics; Medical equipment; Microprocessors; Physics; Piezoelectricity; Sensors; Very Low Frequencies; Wireless sensor networks
• ISSN: 1742-6588; 1742-6596; 1742-6596
• DOI: 10.1088/1742-6596/660/1/012085

Harvesting energy from ambient mechanical vibrations is a smart and efficient way to power autonomous sensors and support innovative developments in IoT (Internet of Things), WSN (Wireless Sensor Network) and even implantable medical devices. Beyond the environmental operating conditions, efficiency of such devices is mainly related to energy source properties like the amplitude of vibrations and its spectral contain and some of these applications exhibit a quite low frequency spectrum where harvesting surrounding mechanical energy make sense, typically 5-50Hz for implantable medical devices or 50Hz-150Hz for industrial machines. Harvesting such low frequency vibrations is a challenge since it leads to adapt the resonator geometries to the targeted frequency or to use out-off band indirect harvesting strategies. In this paper we present a piezoelectric based vibrational energy harvesting device (PEH) which could be integrated into a biocompatible package to power implantable sensor or therapeutic medical devices. The presented architecture is a serial bimorph laminated with ultra-thinned (ranging from 15μm to 100μm) outer PZT "skins" that could operate at a "very low frequency", below 25Hz typically. The core process flow is disclosed and performances highlighted with regards to other low frequency demonstrations.